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Messages - Nevada Dave

#1
Factory 10mm ammo / Unbderwood's 135 gr. Ammo #231
January 06 2015 08:23:04 PM MST
     Hello Gentlemen (and perhaps Ladies)!  I'm new to this forum (as a registered member) but I've been snooping around here for a year or so.  There's a wealth of solid information to be gleaned and I'm not ashamed to admit that I never work up a 10mm load without first checking this nifty site.  Thanks for your scientific approach . . . it compliments my own fastidious mindset.  Therefore, I've decided to officially join (smile).   I'm also the proud owner of 3 Tanfoglio-made 10mm Witnesses (2, all-steel 4.5" and a handsome 4.5" Stock II).  Even though I've been shooting & handloading for over 6 decades, I've only been introduced to the 10mm Auto since late 2013.  I love them so much that they're now my dedicated CCW's.  Heavy but Manly, none-the-less!
     I suppose I joined because I have a concern with Underwood's ammunition.  Some of you seem to be good friends with the owner so I'll try not to step on your toes and be "scientific".  Anyway, about a year ago I ordered a few boxes of their Item #231 (135 gr. Noslers).  Since I chronograph more than I target shoot or hunt, I immediately ran 5 over the screens and found some REALLY fast cartridges.  I was semi-elated at the time because I thought I had a "fast" barrel.  My first 5 rounds averaged 1,699 fps (advertised at 1,600 fps).  About 9 months ago I chronographed 5 more from a more recent purchase.  These averaged 1,568 fps which would be in line with what Underwood advertises.  Yesterday, I was chronographing pressure loads for a new load I'm working on and included a bunch of factory ammo for reference points.  Long-story-short, I touched off another "HOT" Underwood 135 gr.; this one at 1,729 fps!  I immediately knew there was a problem due to the added recoil & enormous flash/bang.  All my other "pressure" rounds & 21 test rounds were as expected (except I discovered that Longshot needs a true magnum primer and 800-X produces more pressure than Longshot at the same velocity) . . . but I digress.  The good news is that my Witness handled this errant round without a hiccup (or even a "smile") but had this round been fired on a warm summer (Nevada) day in a "generous" chamber, there might have been a catastrophic event.  I purchased this older "hot" ammo in November 2013 and they each had a Starline headstamp.  As I mentioned, I've since made another purchase but the newer lot has Underwood's headstamp.  Unfortunately, I've mixed the two lots together so I can't confirm the lot number of the older errant rounds.  I'm a safety freak so it concerns me that I might someday ignite an Underwood cartridge that blows my hand off.  Perhaps the older "hot" ammo was stuffed with 800-X at that time?  Indeed, we all know how easy it is to inadvertently throw in a few extra "cornflakes" in the case.
     Has anyone else experienced this problem with Underwood?  I stopped using Double Tap ammo (in 45 ACP) a few years ago because of this same problem.
     Thank you for this fantastic forum and for the effort you folks go through to make things "scientific"!  I'm certainly not a 10mm expert but I'd be happy to assist anyone with their handloading quandaries . . . or to find a good family law attorney (another smile).
     Best regards from Nevada, USA!